The idea of the Paleo diet was born in the 1970’s and became widely spread after 2000. This theory sustains that, for optimal health, one should return to the eating patterns of our hunter-gatherers ancestors: this may seem logic since we evolved as them for milions of years.
However, the theory gets wrong since it sustains that our ancestors ate a lot of meat and very little carbs; in most cases this is not true!! (people like the Inuit could be an exception since are little natural vegetal resources of nutrition in their direct environment). In fact, the vast majority used to rely mostly on plants and only ate meat when they had killed an animal.
Eventhough humans aren’t naturally adapted to eat animals (we actually have to cook it to digest it well), meat was, nonetheless, very precious for hunter-gatherers. This is because it provides a lot of calories and thus avoids humans to have a calorie deficit.
Also we have to bear in mind that evolutionary “good” doesn’t mean healthy and longevity-promoting. Remember that evolutionary the goal in people’s life is to have a lot of offspring, not to live long. Extra calories from meat in scarse periods could avoid temporary infertility and thus increase their number of children.
I would definitely not recommend a paleo diet because of this reasons, and a whole lot of others.